<template>
    <div>
        <h1>当前求和为：{{sum}}</h1>
        <select v-model.number="n">
            <option value="1">1</option>
            <option value="2">2</option>
            <option value="3">3</option>
        </select>
        <button @click="increment">+</button>
        <button @click="decrement">-</button>
        <button @click="incrementOdd">当前求和为奇数再加</button>
        <button @click="incrementWait">等一等再加</button>
    </div>
</template>

<script>


export default {
 name:'SumCount',
 data() {
    return {
        sum:0,
        n:1
    }
 },
 methods:{
    increment(){
        this.sum += this.n
    },
    decrement(){
        this.sum -= this.n
    },
    incrementOdd(){
        if(this.sum%2){
            this.sum += this.n
        }
    },
    incrementWait(){
        setTimeout(() => {
            this.sum+=this.n
        }, 3000);
    }

 }
}
</script>

<style>

</style>